Milking machine teat cup



Oct. 29, 1940. w. A. scoTT MILKINGA MACHINE TEAT CUP Filed Feb. 2 7. 1939 ////////l/////////////// I/ I//// I//// r//////////////////////// l/////////////////////// l// r// l//////////////////////////////// Patente d oct. 29,- 1940 improved means UNITED STATES -PATENT OFFICE j MILKING MACHINE TEAT CUP I V Walter A. Scott, Poughkeemie, N. Y assignor t i The De Laval Separator Com N. Y., a corpo-ation or New Jersey Inteat cups comprising an outer rigid metal shell or cup proper, an inner rubber liner and 4 'a milk outflow tube, it is customary to expand the shell and, in the circum the upper end of feren-tia seat thus formed, conflne the corresponding end of the liner by means of a ring or disc, this end of teat.` It is also common to bend the lower end of the liner around and outside the corresponding end of the shell and to confine its extremlty against the shell by means of a cap or head on the endof a milk outflow tube.

One of the serious objections to the described means engaging the lower end of the liner with the lower end of the shell and the cap of the milk outflow tube, and which renders such engaging means defective and indeed inoperative, is the creeping of the stretched lower end of the liner. Whether or not the annular chamber between the shell and liner is subject to pneumatic pulsations, the liner is under substantial longitudinal tension and this tension causes a creep- 'ing action that often results in the slippage of its extremity down around the lower edge of the shell, thus wholly destroying the holding action of the cap and and shell.

The object of freein'g the liner from both cap my invention is to provide an' for securing the lower end of the liner between the shell and the' cap oren& larged head of the milk outfiow tube in such manner asto insure against slippage and thus maintain the liner in proper tension andavoid all risk of detachment.

The drawing is a vertical sectional view oi a teat cup embodying my invention.

The teat cup is of the double-chamber type in which an' innerchamber, enclosed in a flexible and elastic liner, is under a constant low pneumatic pressure (partial vacuum) while an outer annular chamber, enclosed between said liner and a rigid shell, is subject to altemating high and low pneumatic pulsations (atmospheric and partial vacuum).

The upper end of the flexible and elastic rubber liner a may be secured to the upper end of the rigid shell b in any efl'ective known way, such as by distending the upper end of the liner by means of a teat-engaging disc c, which disc, with the upper end of the liner bent around it, is seated in the enlarged upper' end d, of the shell. The disc c is usually made of rubber reini'orced by a metal ring c' embedded therein.

The bottom oi' the shell is provided with a contracted neck e having at'its lower extremity an the cup beingslipped over the Application February 27, 1939, Serial No. %8,625 (c. neser outwardly extending circumferential bead f. 'I'h walls of the body and neck of the shell extend parallel to the axis of the shell. The lower end of the liner is pulled down within and against the shell neck and then outward and around the 5 bead f about 225 and then up in a reverse direction about 45 so as to extend parallel to and against the outer wall of the shell neck. The body of the liner, when thus stretched, has within the shell a cylindrical contour of-an external 10 diameter equal to the internal diameter of the shell neck, leaving an annular air space between it and the body of the shen.

The cap or enlarged head of the milk outflow tube g is so shaped that its internal contour, when 15 applied to the shell with the liner bent around it as described, conforms to the contour of the lower end of the shelf and the bent-around end of the liner; that' is, its inner wall, ator about the junction of its shouldered portion with its 20 enlarged diameter portion h, is provided with an internal circumferential recess i opposite and complementary to the outwardly extending bead f at the lower extremity of the shell and the part of the liner bent around the bead, while 2 the part of the' head above the recess i extends parallel withthe axis of the shell and surrounds and contacts with the turned-over extremity of the liner.

While the head h. ofthe milk outlet tube g is,- preferably, of less flexibility and elasticity i than the liner, it must have suflicient fieiibility V supped into holding po r i 0105913' hug the liner as .above described. Thus the head` h,

shellneck e, and the lower end of the liner insid and outside the shell neck all extend in parallel relationship with each other and with the axis of the teat cup except at the locus of the head f and the complementary recess i. The head h is of such length that its upper edge abuts against the shoulder joining the body b and neck'e of the shell, thereby preventing dirt and moisture 'from entering the recess k between which is bent around the bead 35 the upper endof the head and the adjacent part of the shell.

It is found that, in actual use, the llner is held securely in position and is absolutely prevented sirom creeping or slippage, so that the liner maintracted at its lower end to form a neck of a 'substantially uniform and comparatively small diameter connected with the body by an annular shoulder, the neck having an outwardly project ing circumferential bead at itsextremity, the lower end of the liner extending within and in contact with said neck and around said bead and upwardly outside and .in contact with said neck( and a milk flow tube having an expanded head provided in its inner wall with a recess complementary to said bead and contracted above said recess to extend in parallel relationship with said neck and of such internal diameter, substantially less than the external diameter of said shoulder, as to contact with and conflne the upwardly extending extremity of the liner against said neck. said expanded head having sufiicie'nt fiexibility and eiasticity to allow it to be slipped into position over the part of the liner extending around said bead until the bead engages the recess and to then grip the extremity of the liner above the bead and of such length that its upper end abuts against the lower side of said shoulder, whereby the ,lower end of the liner is' prevented from creeping or slipping and the entrance of dirt or moisture into the space between said bead and shell is efi'ectually excluded.

WALTER A. SCOTT. 

